LOL....Federer does look a bit fragile regarding his frame. Nadal's arm flexed does not lead me to the conclusion he used steriods as someone mentioned above. I have never used steriods and my arm is a little bigger than his still keeping the muscle tone.

Federer's no shirt pic cracks me up though.....of course he's in incredibly good shape (without those rippling biceps). I believe we have forgotten what it truely means to be "fit" and "in-shape"......it as little to do with the size or tone of one's muscle.